Get rid of /reduce Noise in Cycles Render
There are some general tips and guidelines, I am sure you can find something in Google as well, this article made a while ago is still today relevant and can help you to understand more about it:

https://www.blenderguru.com/articles/7-ways-get-rid-fireflies

Edit:

The guidelines are:


Use Bigger Light Sources (Bigger lamps or blurred HDRI)
Use Bigger Shadow Sizes
Use "Multiple Importance Sampling" for HDRs
Use 'Filter Glossy'
Check "No Caustics" (Trade-off losing some of the light information)
Use "Clamping" (Trade-off dampening highlights)
More Samples (Trade-off more render time)


For simple projects, I recommend you to enable Simplify:



Essentially it simplifies your shaders, mostly glossy shaders, to render faster, this will give you the advantage to increase render samples, thus, decreasing noise areas.